Head: Paper mache over a 15 inch ball. About 12 layers making it a 1/4 inch thick, wrapped in lycra or similar material who's name escapes me, and glued on with spray adhesive.
Mouth: For fitted chicken wire and leggings for seethroughness.
Eyes: Styrofoam balls with LED lights.
Ears: Light weight high durability foam my dad got at work, not sure where else to get it, but that's wrapped in lycra type stuff too. The ears also have a trim of EL wire, making the glowie stuffz.

It took about a month, but that was completely on and off, I could have finished in a week if I really needed to.